Reduced time remote access method

ABSTRACT

Several techniques for reducing the amount of time between initiation of a terminal request through a dial-up telephone line and the actual initiation of transactions between the terminal and a host computer. By using a ring down or hotline circuit configuration dialing and call setup time can be saved. By using cut through techniques to gain direct access to the IXC switch, time can also be saved over conventional techniques. With the ring down use or cut through procedures no login procedure is necessary to ensure secure access to the host computer. The ring generation period is shortened to just an interval sufficient to allow the host modem to recognize the ring, with the ring indication period also begin shortened. The modems can be set to fixed baud rates, but in a more preferred embodiment the terminal modem transmits the originate carrier prior to the host modem picking up the line. The host modem then senses the originate carrier quickly and provides the proper answer carrier. If an originate carrier of an improper baud rate is provided, speed negotiation commences immediately. If no originate carrier is provided within a given time, a fall back to conventional techniques is used. The silent interval prior to operation of the host modem is removed. After the carriers are both provided, normal connection to the host computer is made and the transaction completed.

This application is a continuation-in-part of application Ser. No.615,931 filed Nov. 19, 1990, issued as Pat. No. 5,144,651 on Sep. 1,1992.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to communication techniques used betweena remote terminal and a host system, and more particularly to ways ofreducing the time from initiation of the communication sequence by theterminal to commencement of transaction processing between the terminaland the host.

2. Description of the Related Art

With the advent of microprocessors and advances in telephone system, ithas become possible to have many remote terminals call central hosts toaccess data. One of the common uses for this data access is credit cardauthorization. When a customer at a remote site wishes to make a creditcard purchase, authorization must be obtained to determine if thetransaction should be completed and credit extended. The process isinitiated by passing the credit card through a magnetic card reader in aterminal or entering the credit card information manually into theterminal. The terminal then proceeds to connect itself through atelephone network to the host system. After the telephone connection isestablished and the modems establish a communication link, the hostsystem is queried to determine if the transaction should occur and, ifso, an acknowledgment is returned to the terminal and the transaction iscompleted at the remote location.

A problem arises regarding the length of time required for the terminalto access the host in combination with the cost of the telephone orother lines necessary to perform the connection of the modems. Ifconventional dial-up and modem technology is used, an average time tocomplete the connection, establish communications and initiate thetransaction is on the order of 30 seconds. This has generally beendeemed unacceptable in that the consumer at the remote location mustwait this time and then a relatively short transaction time before thepurchase can be completed. A conventional dial-up line is a relativelyinexpensive connection and so of great interest to those parties whichmust maintain hundreds of these remote locations, but the performancedrawbacks have been considered unsatisfactory.

One conventional way to resolve this connection and communication timeproblem has been the use of a multi-drop leased line. In thisenvironment a number of remote locations are connected to a singleleased line. A master modem at a host location sequentially polls themodems in the terminals at the various remote locations to see if theyhave data to transmit. If they do, communication is established betweenthe two modems and data is transmitted to perform the transaction. Whilethe performance is quite acceptable at approximately 5 to 7 seconds percomplete transaction, the cost is in the range of eight times greaterthan dial-up technology. However, the added cost has been borne by thevendors because the conventional dial-up technology connection time hasbeen unacceptable and no other generally acceptable solutions wereavailable.

A revolution is currently in progress in the telephone communicationsarea with the advent of digital processing and the use of digitalcomputers in switching operations. Large long distance networks operatedby inter-exchange carriers (IXC's) and to some extent local exchangecarriers (LEC's) are adopting complete digital systems which correspondin varying degrees to the CCITT ISDN standards, the proprietarysignalling portion of which is referred to as SS7, or Signaling System7. These systems, and the various protocols and capabilities of such asystem, are known to those skilled in the art. These standards andequipment and the various computer systems which operate them haveallowed significant advances in the capability and features which can besupported.

One exemplary feature which has been improved is called a ring down orhot line technique. In a ring down system, the handset of a telephone islifted, the telephone thus going off-hook, a signalling arrangementdetects the off-hook condition and causes a predetermined telephone at aremote location to ring. No dialing is necessary. Conventionally thiswas done only for short distances using a dedicated line. This techniqueallowed quick connections but was quite expensive and effectivelylimited to point-to-point connections in local areas. The possibilitiesof ring down or hotline circuits have increased greatly with the new SS7based signalling technology. One exemplary provider of this new serviceis Sprint, which provides the "VPN Hotline" service. The VPN Hotlineservice allows more flexibility than the conventional ring down circuit.Preferably, for best performance a direct access line (DAL) is providedfrom the customer site to a carrier point of presence (POP) at each end,with all switching between the two POP's being handled over the IXC'sconventional shared switch network. The insertion of the POP's and theshared switch network allow the connection to be made between any twolocations, assuming the locations are connected to the equipment whichworks according to the new protocol. The system performs basically asfollows. The process commences when the caller goes off-hook to initiatea call. This off-hook condition is detected by the signalling equipmentin the POP, with the computer system in the shared switch network thusknowing the effective address or identification of the caller. Becauseof the DAL connection, the caller is considered "on net," that is,positively identified by the shared switch network. An address oridentification lookup from a computer database is then performed todetermine where the call is to be placed. The final destination addressor identification is provided by the lookup, with this information beingpassed through the Signaling System 7 compatible or similar network. Thenetwork passes the connection information to the receiving POP and thereceiving telephone is made to ring. This VPN Hotline service providesquick access because no actual dialing is done and the LEC switchingarrangement is by passed. Instead, the computer system senses via aconventional signalling arrangement that the originator has goneoff-hook, performs a table lookup and then initiates the connectionprocess to the answering or receiving telephone. Thus the use of theavailable advanced technology has allowed the hotline or ring downcircuit to be extended across long distances.

One disadvantage of this VPN Hotline System is that it can only beprogrammed, at present, for a single point to point connection, but thisis not a problem in the remote location to a central host for a creditcard approval situation. The location of the host is fixed, thereforethe lack of outgoing call location flexibility is not a problem. Theoriginating location retains a unique identification, such as a phonenumber, so the remote location may still receive a call usingconventional techniques. The use of the VPN Hotline technique aloneallows a savings of approximately 15 seconds over conventional dial-upsystems. Where the various portions of time are gained will be explainedin detail later. However, if the conventional average time for dial-upline is approximately 30 seconds, as has been determined the variousexperiments, this reduction of approximately fifteen seconds stillleaves approximately 15 seconds total connection establishment time.This is still relatively high and any further reduction is, of course,desirable.

Sprint has developed a more flexible alternative to the VPN Hotlineservice discussed above. The new service is referred to as "SwitchedAccess VPN." In this service the customer dials the carrier equal accesscode and an end of dialing code to establish a cut through access to thecarrier's network, for example 10333# in the case of Sprint. In thecurrent majority of cases where the Sprint SS7 network is not fullyinteroperable with the LEC, this dial sequence causes the customer'stelephone number to be forwarded to the carrier's POP by an MFsignalling sequence which includes as a significant element theautomatic number identification (ANI) sequence. The POP performs anidentification lookup based on the telephone number to determine whichfeatures are available for this user. This lookup determines if theSwitched Access VPN feature is available, and if so, which type. If theSwitched Access VPN feature is available, the customer is now clearedand now is considered on net. Until the ANI lookup clears the customer,the customer is considered "off net," that is, unidentified and notsecure. Two types of Switched Access VPN are available. In the first,referred to as immediate, only a single destination is available. Inthat case the POP has retrieved the destination address as part of thelookup and simply provides the destination address through the remainderof the network to establish the connection. In the second type ofSwitched Access VPN, referred to as delayed, numerous destinations canbe accessed. If the POP determines that the second type is set up forthis particular calling location, then the POP provides a dial tone tothe customer, the customer then provides a destination number, which isthe full digit destination on net number, and end of dialing code to thePOP. The on net number is the number used internally by the IXC'snetwork. When the POP receives the on net number, preferably a sevendigit number, it retrieves a table for that destination number and doesa validation lookup to determine if the particular customer isauthorized by checking for the ANI information. If not listed, thecustomer is not authorized and a failure code in the form of a recordedannouncement is returned. If listed and thus authorized, the callproceeds. Alternatively, fewer digits can be used in a speed dialarrangement, but the resulting speed dial lookup offsets the dialing ofthe extra digits. The destination address or identification based on theon net number is used and provided through the network to establish theconnection. While some additional time is necessary because of thedialing of the digits, this service provides capabilities to reachmultiple destinations.

The previous section described a service referred to herein as MFSwitched Access VPN which is used when the POP and the LEC are not fullyinteroperable using SS7. In certain areas today and more areas in thefuture, the POP and the LEC are fully interoperable. In these cases theSwitched Access VPN sequence is slightly different. After the customercompletes the cut through request, the POP and LEC communicate out ofband according to the SS7 protocol. Included in this communication isthe automatic number identification of the customer. The POP thenproceeds as stated above. The interoperable Switched Access VPN serviceis significantly quicker than the MF Switched Access VPN service becausethe use of the SS7 out of band signalling greatly reduces the timenecessary to transmit the ANI and other signalling information ascompared to MF signalling.

As compared to VPN Hotline, delayed MF Switched Access VPN may add asmuch as 2 seconds in the average case and immediate interoperableSwitched Access VPN may be 1 second faster. Delayed, interoperableSwitched Access VPN and immediate MF Switch Access VPN will add timesbetween those limits. One advantage of all the Switched Accessvariations is that connection to the LEC is simplified. Where theoriginal VPN Hotline connections generally required loop startconnection to the LEC, the Switched Access variations utilizeconventional 1FB or 1MB business line switched connections. The DALs andloop start are no longer required. Thus a small trade off in timegreatly simplifies the actual ordering, wiring and provisioning of thesystem.

SUMMARY OF THE INVENTION

The present invention includes techniques for further reducing the totalconnection time from time of initiation by a remote terminal tocommencement of the actual transaction. Several different options areused to reap varying levels of reduction in the total period. One of thetechniques used to reduce the total time interval is the removal of anypassword or login procedure to the host computer. Because the VPNHotline, Switched Access VPN, or similar techniques utilize databaseinformation contained in the IXC's computer system, the host computerdoes not actually have a telephone number per se and thus cannot becalled using conventional dial-up techniques. Accordingly, it is notpossible for the host to receive calls from any location other thanthose programmed into the databases in the various computer systems inthe switching network. Thus, the network is secure, assuming integrityof the databases, and no login procedure is considered necessary. Thisresults in the savings of approximately six-tenths of a second in anexemplary case.

Further time can be saved by setting the modems at the remote terminaland host to operate at a fixed baud rate and not do a selective baudrate handshake determination. By fixing the modems to bypass this baudrate handshake, approximately 2.2 seconds can be saved to further reducethe overall time. However, this technique does have certaindisadvantages in that if terminals of differing baud rates areconnecting to the host, then either a greater number of modems must besupplied or the chance of receiving a busy signal is increased. Onealternative increases cost while the other increases average connectiontime. These alternatives may be acceptable in given cases and theembodiment may then be preferred in some cases.

A more preferred alternative to further reduce the connection time is tohave the remote terminal modem automatically transmit the originatecarrier instead of conventionally waiting to receive an answering tonefrom the host modem and recognize it before transmitting an originatecarrier. The modem at the host is converted to expect receipt of anoriginate carrier and if so received, automatically transmits anappropriate answer carrier, if the modem can operate at the rateindicated by the originate carrier. Thus, using this technique theentire handshake interval can be completed in one-half second if nospeed matching is required. If the host modem can not operate at therate initially indicated by the terminals modem's originate carrier, thehost modem commences negotiation of a baud rate by responding with acarrier according to conventional handshake and speed negotiationtechniques, still having effectively bypassed several steps in thenegotiation. If the host modem does not receive the originate carriersignal within a given time period, it can then default to conventionalanswer tone provision and full handshaking and speed arbitration. Thus,multiple speed modems of both conventional and originate carrier typescan be used to access the host.

Yet another area to further reduce the connection time is by reducingthe ring interval. The ring signal need be present only for a sufficienttime to be detected the host modem. An additional 1.5 seconds can besaved with this short ring arrangement. With some signallingarrangements, such as E & M signalling which is preferably used in theSwitched Access VPN embodiments, the ringing interval can be effectivelyeliminated in its entirety, resulting in a full 2 second savings.

An additional area to further reduce the total time is the removal of asilent interval after a ring indication is received by the host modem.The originate modem would preferably be providing the originate carrierfrom a period shortly after a loop is seized and before the telephoneconnection is completed. After the host modem has sensed the ring signaland picked up the line, the host modem senses this presence of theoriginate carrier and begins transmitting the answer carrier, assumingit was a proper speed. In the Switched Access VPN techniques, theoriginate modem would begin providing the originate carrier after thelast digits in the sequence are dialed, so that again the originatecarrier is provided before the telephone connection is completed and thehost modem answers, so that the host modem can quickly sense thiscondition and immediately begin transmitting an answer carrier, againassuming the originate carrier was of a proper speed. Omitting anysilent interval allows a savings of approximately 2.4 seconds.

Additionally, the terminal modem preferably senses dial tone veryquickly, such as in 100 ms, and tone dials very rapidly, preferably only100 ms per digit. These operations also allow time savings.

By using all of these techniques in conjunction with the VPN Hotlineservice or its equivalent, it is possible to reduce the overall time bya great deal, to an exemplary 5.7 seconds in given examples, fromapproximately 30 seconds in a conventional dial-up arrangement.Utilizing the delayed, MF Switched Access VPN service allows thereduction to an exemplary 7.8 seconds in given examples, while utilizingthe immediate, interoperable Switched Access VPN service allow areduction to an exemplary 4.6 seconds. It is, of course, noted thatthese times are exemplary and will vary by location but the generalconcept will produce equivalent results in each given instance. Thus, bythe combination of these various events, the transaction time can bereduced as desired. It can be reduced first by several simple steps andstill use conventional modems. If greater time savings are desired, newmodems with revised handshaking and silent interval alternatives can beused with the time being dramatically reduced. Thus the invention allowsdial-up type switched access with its much cheaper cost to be usedinstead of the more expensive leased line options with sufficientperformance to reduce consumer impatience.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the present invention can be obtained when thefollowing detailed description of the preferred embodiment is consideredin conjunction with the following drawings, in which:

FIG. 1 is a block diagram of the telephone system according to thepresent invention using the VPN Hotline service;

FIG. 2 is a timing diagram of a dial-up line according to the prior art;

FIG. 3 is a timing diagram of the transaction sequence of one embodimentof the present invention using a particular modem convention and the VPNHotline service;

FIG. 4 is a timing diagram of the transaction sequence of FIG. 3 bututilizing a different modem convention;

FIG. 5 is a timing diagram of the transaction sequence of an alternateembodiment using modified modems to reduce the connection times and theVPN Hotline service;

FIG. 6 is a block diagram of the telephone system according to thepresent invention using a Switched Access VPN service;

FIG. 7 is a timing diagram of the transaction sequence using themodified modems and the delayed, MF Switched Access VPN service; and

FIG. 8 is a timing diagram of the transaction sequence using themodified modems and the immediate, interoperable Switched Access VPNservice.

These figures are not intended to define or limit the invention, but areprovided solely for the purpose of illustrating preferred embodiments ofthe invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 discloses an end to end circuit configuration of a telephonesystem incorporating a preferred embodiment of the present invention. Aremote terminal 10 includes a terminal modem 12. In the preferredembodiment terminal modem 12 is a 1200 baud modem that operatesaccording to the Bell 212A sequence, or alternatively the V.22 bis,V.32, V.32 bis or other sequences. 1200 baud operation is preferredbecause speed negotiation or handshaking with the 1200 baud Bell 212Aspecification takes less time than handshaking with the V.22 bisspecification. For example, use of a V.22 bis handshaking sequence andoperation at 2400 baud sends the characters at twice the speed, but theslower V.22 bis handshaking time actually increases the total time fromstarting communication to completion of most short messages. Thus theadded cost of the conventional 2400 baud modem is not offset by areduction in total time of interest. However, the technique will operatewith any baud rates, commonly up to 56 kbaud, and operation at thesehigher baud rates may be desirable for longer messages or transactions.

The terminal modem 12 can be dedicated to the telephone line or mayshare it with other units and can be any type device that can seize atelephone line to indicate an off-hook condition. The terminal modem 12is connected to the serving local exchange carrier (LEC) office througha two wire loop 14. In the preferred embodiment for use with the VPNHotline service or its equivalent, this two-wire loop 14 is a privateleased line also known as a direct access line (DAL). The terminal modem12 is connected to the serving local exchange carrier (LEC) officethrough a conventional two-wire loop 14. The two wire loop 14 isconnected to a channel unit 16 in the serving LEC office. The channelunit 16 includes the proper foreign exchange subscriber (FXS) equipment18 for connection to the two wire loop 14. The FXS equipment 18 isconfigured to provide loop current and may detect closure based on loopstart. Loop start is such that when the terminal modem 12 requests aline by going off hook, the loop is closed and current begins to flowthrough the two wire loop 14. The FXS equipment 18, or alternatively thepoint of presence (POP) equipment, senses this current flow in the loopand thus recognizes that the terminal modem 12 is requesting a datatransmission or is acknowledging a ring indication.

The serving LEC office channel unit 16 is connected to a switch SWA inthe telephone company shared switch network 20. This connects thechannel unit 16 to the telephone company network 20, which then cantransfer the information to a host unit 32. The switch SWA senses thatthe line is being requested. The switch SWA performs the proper look-upand then according to the VPN Hotline or similar techniques communicatesto a switch SWB in the IXC telephone company network 20 which is locatednear the host unit 32. Switch SWB communicates to a point of presenceunit (POP) 22 of the preferred carrier of the user. The POP 22 in thepreferred embodiment is directly connected to the host channel unit 24,preferably by a T1 link, but alternatively can be connected through areceiving LEC office 27. The disadvantage of having the connection madethrough a receiving LEC office 27 is that it may add approximately 5seconds to the total transaction time, but this technique may berequired depending on the number of connections in the host unit 32. Ifthe number is low then the added expense of the direct connection to thePOP 22 may not be justified. It is noted that connection through to aPOP may be necessary if the LEC equipment is not able to operateaccording to the necessary protocols. It is further noted that a POP maybe included in the circuit between the serving LEC and the telephonenetwork 20 for similar reasons. The receiving channel unit 24 isconfigured in a similar manner to the serving channel unit 16 in that ithas FXS loop equipment 26 which provides loop current to a two wire loop28, which is in turn connected to a host modem 30 coupled to the hostunit 32 through a communications processor 31. The communicationsprocessor 31 is used to convert the asynchronous serial signals used bythe host modem 30 into synchronized digital signals used by the hostunit 32. In the preferred embodiment the communications processors 31handles the flow of transactions to the POS terminal in accordance withthe VISA I or equivalent protocol and to the host in accordance with theX.25 protocol. When the host modem 30 senses the ring indication, itcloses the loop by going off-hook and the current begins to flow at thereceive end.

Thus, operation in this circuit of FIG. 1 proceeds as follows for a VPNHotline service or its equivalent. A remote terminal 10 is activated andthe terminal modem 12 goes off-hook and draws loop current. This loopcurrent draw is sensed by the channel unit 16 and switch SWA. Switch SWAperforms the data lookup to determine the routing information for a callbeing placed by the terminal modem 12 and transfers the call and routinginformation through to switch SWB according to the SS7 protocol. SwitchSWB connects to the POP 22 based on the signalling information providedby switch SWA. The POP 22 routes the call to the channel unit 24, whichthrough the FXS loop equipment 26 and over the two wire loop 28, andprovides a signal to the host modem 30 that a call is being received.The host modem 30 senses this ring indication and closes the loop, thusestablishing a complete circuit between the terminal modem 12 and thehost modem 30. Any modem speed negotiation and login proceduresnecessary to the connection process and the actual transaction can thenoccur.

It is noted that preferably the serving LEC office contains SS7 or ISDNcompatible equipment which is interoperable with SS7 compatibleequipment of the IXC so that a direct connection is not necessary to aPOP which could exist between the serving LEC office and switch SWA.This is a desirable condition to improve performance and save expensebut, of course, depends upon the equipment being provided by the servingcarrier and the interoperability of signalling systems between the IXCand the LEC.

To fully understand the operation and improvements provided by thisinvention, it is useful to describe and analyze a conventionalconnection developed using a standard dial-up line with its varioustimings. Please refer to FIG. 2 in connection with this description. Itis noted that in all the timing diagrams any values given are consideredto be approximate or average values, with the absolute value varyingdepending upon various efficiencies and speeds of the communicationsequipment installed. The illustrative values were developed in a seriesof experiments to develop some idea of the actual values involved.However, in all cases the actual protocol being developed will providesimilar savings of time based on the actual times in a givencircumstance.

The sequence in a conventional system begins at time zero with theremote terminal 10 formatting the user data into a transaction andsending a command to the terminal modem 12 to go off-hook. This intervallasts approximately 1.0 seconds, during which time the terminal modem12, having initiated the call by going off-hook, checks the phone lineto determine that a dial tone is present and returns a failure code ifit is not present. For a period of approximately one second the terminalmodem 12 tone dials the telephone number of the host modem 30 or modempool. Thus the time required to initiate a call is approximately 2.0seconds. The telephone company or telco system 20 receives this dialinginformation and proceeds through call setup and ring generation. Thisperiod was measured in a series of experiments to be approximately 17.0seconds for that particular circuit path. This number of course willvary by location. The last two seconds of this period include the ringgeneration interval which is indicated by the presence of the RI or ringindication signal by the host modem 30.

After the host modem 30 recognizes that a ring signal is present by theremoval of the RI signal, the call is answered by the host modem 30going off hook. Modem negotiation begins with a 2.4 second silentinterval. This silent interval for in band signalling associated withbilling is presently mandated by the Federal Communications Commission.After the silent interval the host modem 30 provides a 2100 Hertz answertone for a period of approximately 3.3 seconds. It is noted that theprotocol being described is the V.22 bis protocol and is exemplary of aparticular protocol, but it is noted that other protocols andhandshaking schemes can be performed with similar events occurring.During this interval, at approximately 1.5 seconds after the start ofthe answer tone in the example, the answer tone is detected by theterminal modem 12, which then provides an originate carrier. Theoriginate carrier is eventually detected by the host modem 30 and ananswer carrier is then provided. At the time the 3.3 seconds of the 2100Hz answer tone is completed, the host modem 30 raises a DSR or data setready signal to indicate that the handshaking or negotiation sequence iscommencing and provides an answer carrier. Approximately one secondafter the answer carrier is started, the host modem 30 concludes thehandshake sequence and raises a CD or carrier detect signal to indicatea ready status. The terminal modem 12 will have previously raised itscarrier detect signal when it completes its portion of the handshakesequence and recognizes the answer carrier. The remote terminal 10 goesinto a programmed pause to allow various portions of the system tocomplete their operation prior to sending or transmitting data.

When the carrier detect signal of the host modem 30 goes to a highstate, this is an indication to the communications processor 31 thatcarriers are present and data communication can commence. Approximatelyone second after the presence of the answer carrier is indicated, thecommunications processor 31 is conditioned to conduct datacommunications. In the specific units in the experimental sequence a TIDor terminal identification request was ignored by the remote terminal 10and this time built into the programmed pause. A timing character istransmitted by the remote terminal 10 after the completion of itsprogrammed pause. The character transmitted is preferably a capital Abecause this allows convenient interval timing loops to be used toeasily determine the baud rate of the transmitting terminal modem 12.This period from carriers present to completion of baud ratedetermination was approximately 3.0 seconds in the experiments. A periodafter the baud rate character is sent, the terminal modem 12 transmitsthe login information to allow the remote terminal 10 to log into thehost computer 30. This login signal is received by the communicationsprocessor 31 and after approximately 0.6 seconds an ENQ or enquirycharacter is sent to the terminal modem 12 to indicate that login hasbeen completed.

At this point the actual transaction for credit authorization or otherpurposes begins. In an exemplary credit transaction, this may takeapproximately 2.0 seconds, which includes the various addressingprotocol packets and other information which are transmitted. Numeroustransactions protocols or formats can be utilized, but in the preferredembodiment a variation on the VISA I protocol is used. After 2.0 secondsin the experiments the transaction is complete and the remote terminal10 can begin completing the transaction at the remote location. Timingcriticality stops at this point and thus is not described.

In a series of measured tests, this entire interval from remote terminal10 initial request to end of transaction was approximately 32.0 seconds,an unacceptably long period for most consumer transactions. This totaltime can be broken down into four portions. Portion A begins when theremote terminal 10 local transaction is complete and the communicationprocess is started. Portion A includes the time from the completion ofthe local transaction to completion of the dialing of the host phonenumber, including the time the remote terminal 10 requires to send acommand to the terminal modem 12 causing the terminal modem 12 to gooff-hook, the time the terminal modem 12 takes to determine if a dialtone is present and the time required to actually dial the number,including any pauses or special digits that may be required. Portion Brepresents the time required for the telephone company to route the calland complete the ringing cycle at the host location. This time beginsfollowing dialing of the last digit by the terminal modem 12 and endswhen the call is answered following the ring. Portion C represents thetime required for the host modem 30 to answer the call, negotiate aspeed and indicate that the data can be sent by raising the CD signal.Thus Portion C begins when the host modem 30 answers the call and endswhen intelligent data can be transmitted from the host modem 30 to theremote terminal 10. Portion D represents the remainder of time tocompletion of the transaction and includes the login process,transmission of an inquiry, communication of the actual transaction datafrom the remote terminal 10 to the host computer 32, any host processingtime and communication of any response to the remote terminal 10. In theexperiments that were performed, Portion A was approximately 2.0seconds, Portion B was approximately 17.0 seconds, Portion C wasapproximately 6.7 seconds and Portion D was approximately 6.2 seconds.Because of rounding, these may not add up to the 32.0 second value forthe entire period.

In a first series of additional experiments and tests, variousparameters were changed from the conventional dial-up setup. The firstchange was the connection of the terminal through a VPN Hotline or ringdown look-up type arrangement described in the description of FIG. 1.The second change was the setting of the host modem 30 and the terminalmodem 12 at set baud rates to reduce large portions of the handshakeperiod. A third change was the complete removal of the login sequence.An additional change was that auto baud rate determination was not made.

A call sequence for a system including those changes is shown in FIG. 3,with operation as follows. Operation commences at time zero when theterminal requested a connection and the initiation period of one secondcommences. After this one second interval, the loop 14 is seized andcurrent begins to flow. The channel unit 16 at the serving LEC officedetermines that the call is being placed and upon loop seizure initiatescall setup and ring generation. In the experiments this period lastedapproximately 2.4 seconds, 2 seconds of which was the ring indicationperiod. The host modem 30 upon removal of the ring indication signalinitiates the silent interval of 2.4 seconds. After the silent intervalis completed, the DSR signal is raised and a 2250 Hz answer tone isprovided for 1200 baud operation. In the sequence illustrated in FIG. 3the modems 12 and 30 are operating according to the Bell 212A protocoland at a fixed baud rate, with the modem baud rate handshaking disabled.After approximately 1.5 seconds the answer tone is detected by theterminal modem 12, which proceeds to respond and provides the originatecarrier. The originate carrier is quickly detected by the host modem 30and the answer carrier provided. After approximately 1.5 seconds thehost modem 30 concludes that the handshake is complete and the CD signalis raised. Again, the terminal modem 12 will have previously concludedthat the handshake is completed and will have raised its CD signal. Uponthe receipt of the CD or carrier detect signal from the host modem 30,the communications processor 31, which communicates with the terminalmodem 12 according to the VISA I protocol, after approximately 1.7seconds transmits the ENQ character to the terminal modem 12. Theterminal modem 12 receives the ENQ character and the transactionimmediately commences without a login procedure. Again, the transactionlasts approximately 2.0 seconds and completes.

It is noted that a login is not required because according to theoperation of the telephone network 20, the host modem 30 does notactually have a number which is called but merely a designation orlocation contained in the switches SWA and SWB. Because the only accessto this location can be through the switch information data base, it isnot possible to call this number with a conventional dial-up unit andtherefore, no security breach should occur unless the telephone companynetwork 20 switch SWA is reprogrammed. Thus, the login procedure can beremoved, saving approximately 0.6 seconds.

The total average time from terminal request to transaction complete wasapproximately 12.5 seconds in the series of experiments. This reductionfrom approximately 32.0 seconds was obtained in several ways.Approximately one second was saved by not requiring a number to bedialled and another approximately 14.6 seconds was saved in the callset-up and ring generation phase because of the ring down arrangement.By the use of the alternate modem protocol and the fixed baud rateoperation, a period of approximately 3 seconds was saved by theshortened handshake period and the quicker switching of thecommunications processor 31. The login time of approximately 0.6 secondswas also saved just prior to commencing the transaction. The approximatetimes of the various portions equivalent to those of FIG. 2 were 1.0second for Portion A, 2.4 seconds for Portion B, 5.4 seconds for PortionC and 3.7 seconds for Portion D.

FIG. 4 represents a variation of FIG. 3 with a different communicationprotocol between the two modems 12 and 30. In this case, the V.22 bissequence is used instead of the Bell 212A protocol. The primarydifferences between FIG. 3 and FIG. 4 are shown in the period of themodem handshake, where the host modem 30 provides a 2100 Hz answer tonewhich is received by the host terminal 12. This tone is provided for alonger period of approximately 3.3 seconds. After detecting the answertone, the terminal modem 12 provides an originate carrier. After thisoriginate carrier is detected, an answer carrier is commenced by thehost modem 30. After a period of time the handshake is fully completeand the host modem CD signal is raised and connection between the modem30 and the host unit or computer 32 proceeds. Using the alternatestandard of V.22 bis, the approximate total time is 14.7 seconds, withthe change between FIG. 3 and FIG. 4 protocols occurring in Portion Crelating to the modem handshaking and connection, which increased from5.4 seconds to 7.6 seconds.

In FIG. 5 a further optimized timing sequence is shown. In theparticular timing sequence the average time from terminal request totermination of transaction is approximately 5.7 seconds. This isdeveloped as follows. A terminal request is initiated so that after a0.5 second period the loop is seized. This period is (slightly reducedfrom the previous 1.0 second interval by optimizing remote terminal 10operations. This optimization can be accomplished by simplifying theterminal modem 12 checking of the telephone line 14. In the ring downarrangement the majority of the factors that need to be checked areremoved and so the line checking can be limited to simply monitoring forthe presence of any tone and, if obtained, proceeding without furtherchecking. This loop seizure indicates to the telephone company equipmentthat it should commence call setup and ring generation, which lasts 1.0seconds. This interval is reduced by having the ring signal present onlyfor a sufficient time to allow detection by the host modem 30 and thenceasing. The host modem 30 then provides the ring indicator or RI signalfor 0.5 seconds. This is thus a 1.0 second interval instead of theprevious 2.4 second interval. This 0.5 seconds of RI signal can beremoved if E & M signalling is utilized, but this is not preferred inthis embodiment because of other increased complexities. While in theconventional case the terminal modem 12 is inactive during the ringgeneration and indication period, in this embodiment the terminal modem12 is preferably transmitting the originate carrier before the callsetup and ring generation is complete, possibly continuously from theloop seizure. Upon removal of the ring indication signal the host modem30 answers and immediately raises the DSR signal. The host modem 30picks up the line without waiting for a silent interval. As the hostmodem 30 picks up the line it immediately detects the originate carrierwhich is already being provided by the terminal modem 12 and quicklyprovides the answer carrier to the terminal modem 12. The host modem 30is preferably set to default to the desired frequency of the terminalmodem 12, thus eliminating need for baud rate negotiation. Afterapproximately 0.5 second the handshaking is considered fully completedand both carriers have been detected. The carrier detect signals areraised by both the terminal modem 12 and the host modem 30. This raisingof the host modem 30 CD signal indicates to the communications processor31 the need to begin the transmission to the host computer 32. After thesame approximately 1.7 second interval, the ENQ character is sent by thehost modem 30 and the transaction begins. The transaction lasts, for thesake of this description, the previously measured 2.0 seconds period andthen completes. Thus, in this enhanced version, an additionalapproximately 7 seconds have been removed, with a portion coming fromoptimizing the terminal 10, a portion from reducing the ring generationinterval, a portion coming from the removal of the silent interval andanother major portion from the simplification of the handshake based onthe terminal modem 12 providing the originate carrier early so that whenthe host modem 30 goes off-hook, the carrier is quickly detected and theanswer carrier provided.

It is noted that in the embodiment of FIG. 5, the host modem 30 is setto have a default of the speed of the terminal modem 12. However, tofacilitate switchover of a large system to modems utilizing the revisedhandshake procedure or the changeover of modems utilizing the revisedhandshake procedure to different baud rates, it is desirable to have thehost modem 30, or modems in case of the typical modem poolingarrangement, respond to different baud rates or conventional handshakeprocedure modems which need an answer tone for their operation toconnect to the host modem 30 and to varying originate carrierfrequencies. This would simplify the changeover process as it may not bedesirable or feasible to immediately replace all of the terminal modems12 in a very short period of time. This multiple function operation maybe developed in the host modem 30 as follows. Upon going off-hook thehost modem 30 samples for the originate carrier on a selected frequencybased on its default baud rate.

If an originate carrier is detected and the host modem 30 can operate atthe baud rate indicated by the originate carrier, the host modem 30provides the appropriate answer carrier. This is the preferred case andsimplest, as only a relatively few host modems are necessary and theycan be changed over easily and be more complex and yet not overly impactchangeover costs as compared to changing the entire network in a shortperiod. If an originate carrier is detected but the host modem 30 cannotoperate at the indicated baud rate, the host modem 30 returns an answercarrier to perform a speed negotiation process. The two modems 12 and 30then negotiate for an acceptable baud rate. Because the originatecarrier has already been provided, the negotiation process iseffectively started in mid-stream as compared to a conventional casewhich first requires an answer tone. So even the negotiation process isshorter.

Certain further options are available if modems using the V.32 or V.32bis standards are used. For example, V.32 systems must also adjustadaptive equalization settings and other parameters. The host modem 30can sample and store typical settings for its given network and circuitsand attempt to use these stored settings before performing a fullnegotiation process for the settings.

If this originate carrier is not detected within a given period, forexample, 0.3 second or 2.4 seconds to simulate a silent interval, thehost modem 30 determines that a nonoptimized terminal modem 12 is beingutilized in this communication sequence and reverts back to conventionalmodes such as Bell 212A, V.22 bis or V.32 to perform a full baud ratenegotiation and handshake.

Analyzing then the times of the various portions, Portion A is reducedto approximately 0.5 seconds, Portion B reduces to approximately 1.0seconds, Portion C is dramatically reduced to approximately 0.5 seconds,while Portion D remains at approximately 3.7 seconds.

Thus, it can be seen that through the use of several factors thereduction of the time using a dial-up line can be dramatically reducedfrom in excess of 30 seconds to a number just slightly greater than 5,while still maintaining dial-up costs.

FIG. 6 illustrates a telephone system using the Switched Access VPNservice or its equivalent. Again a remote terminal 10 includes aterminal modem 12 such as those previously described. However, in thisembodiment the terminal modem 12 is connected to the LEC 17 via aconventional 1FB, 1MB or equivalent switched line, not the direct accessline of the VPN Hotline embodiment. This use of the 1FB or 1MB linesimplifies the actual ordering, wiring and provisioning of theconnection to the LEC 17. The LEC 17 is connected to switch SWA in thetelephone company network 20 by a conventional Feature Group D switchedtrunk, as used in all equal access calls. With this switched arrangementthe LEC 17 could easily connect to any number of different telephonecompany networks which provide functions equivalent to the SwitchedAccess VPN service of Sprint. The switch SWA in the IXC network 20performs the look-up as discussed in the background and communicates thedestination information to Switch SWB. In this preferred embodimentthere preferably is a dedicated T1 link from switch SWB to the hostcomputer center 32 and it's channel unit 24. This allows numerous callsto be handled simultaneously in a very efficient manner. Additionally,the channel unit 24 could receive T1 links from different telephonecompany networks. The channel unit 24 is connected to a series of hostmodems 30, which in turn are connected to the communication processor31, as described above. In an alternate embodiment the channel unit 24,the modems 30 and the communication processor 31 could be combined onone unit, such as the system provided by Primary Access Corp. of SanDiego, Calif. The Primary Access system preferably replaces the analogmodems with digital signal processing (DSP) units, which perform thedigital equivalent function of the analog modems, so that the entirechannel from switch SWB can remain digital. The T1 link is preferablyconnected with either loop start signalling or E & M signalling. Ineither case, monitoring of the A and B signalling elements to detectring allows almost total reduction of the ring sequence. The X.25portion of the Primary Access system also speeds up the host connectionprocess, effectively reducing host processing time.

Operation according to FIG. 6 proceeds as follows for a Switched AccessVPN Service or its equivalent. A remote terminal 10 is activated and theterminal modem 12 goes off hook and quickly detects the dial tone. Theterminal modem 12 then dials the access and cut through sequence, suchas 10333#. Preferably the terminal modem 12 is configured to detect adial tone within 100 ms and to rapidly tone dial the digits, with eachdigit and the space following each digit being provided for 50 ms each,for a tone dialed digit and its associated space preferably beingprovided for just 100 ms. It has been determined that most of the modernequipment utilized by LEC's and IXC's can readily handle these shortenedtimes. In other cases the times can be extended. The LEC 17 communicateswith switch SWA and transfers the automatic number identificationinformation. The switch SWA performs the lookup as described andproceeds until the destination information is obtained. The destinationinformation is passed to switch SWB according to the SS7 protocol.Switch SWB connects to the T1 link to the channel unit 24. The channelunit 24 provides a ring signal to the host modem 30, which detects thering and goes off hook to complete the circuit to the terminal modem 12.

FIGS. 7 and 8 illustrate timing sequences using the protocol of FIG. 5combined with delayed, MF Switched Access VPN and immediate,interoperable Switched Access VPN, respectively, both in conjunctionwith the Primary Access system. As in FIG. 5, the terminal modem 12provides the originate carrier prior to the completion of the telephoneconnection to the host modem 30. In the particular timing sequence ofFIG. 7, the average time from terminal request to termination of thetransaction is approximately 7.8 seconds, while in FIG. 8 the period isapproximately 4.6 seconds.

The timing of FIG. 7 is developed as follows. A terminal request isinitiated and the terminal modem 12 goes off hook, quickly senses thedial tone, as previously described, and rapidly tone dials the cutthrough sequence for the desired carrier. The required time is anaverage of approximately 1.4 seconds. In the case of FIG. 7, which is adelayed, MF Switched Access VPN example, the LEC 17 then communicateswith the switch SWA, providing information including the ANIinformation. Switch SWA does its table lookup based on the ANIinformation and determines that this terminal 10 is set for delayedoperation and so returns another dial tone to the modem 12. This processtakes an average of approximately 2.4 seconds. The terminal modem 12quickly detects this second dial tone and provides the destinationnumber and shortly thereafter, the origination carrier. The detectionand dialing process takes approximately 1.0 seconds on average. It maybe that in equivalent services the entire dialed sequence can beprovided in one burst, without an intervening dial tone. This wouldreduce the times based on the particulars of the alternate service. Theswitch SWA receives the destination information, performs the validationlookup as previously described and begins the call set up and ringgeneration process. This validation, call set up and ring generationprocess takes approximately 0.5 seconds. The channel unit 24 receivesthe ring indication. In the preferred case this is done by conventionalA and B signalling elements of either loop start or E & M signalling, sothat the ring detection time is almost zero, offsetting portions of thedialing time. Upon detection of the ring signal, the channel unit 24answers the call and establishes a connection to the host modem 30 andthe speed negotiation process begins. At the same time thecommunications processor 31 establishes a connection to the hostcomputer. Thus the approximate time from the completion of carrierhandshake by the host modem 30 until the transaction is complete isapproximately 2.0 seconds. No login procedure is necessary in this case.Security is provided by the lookup and feature verification and ANIvalidation done by switch SWA. The destination number provided by theterminal modem 12 is an on net number, so that when the on net number isrequested in this case, a validation lookup of the destination number ismade to verify that the terminal modem 12, as identified by its ANIinformation, is a source authorized to connect to that on net number. Ifnot, a failure indication is returned. Thus security is maintained eventhough the terminal modem 12 and the LEC 17 communicate over switchedlines. Portion A is thus approximately 1.4 seconds, portion B isapproximately 3.9 seconds, portion C is approximately 0.5 seconds andportion D is approximately 2.0 seconds.

The timing of FIG. 8 is developed as follows. Again the terminal requestis initiated and the terminal modem 12 goes off hook, detects dial toneand rapid tone dials the cut through sequence. This process again takesapproximately 1.4 seconds. The LEC 17 rapidly communicates with switchSWA using out-of-band signalling such as SS7, providing the ANIinformation and other information. The switch SWA performs its tablelookup, detects the election of immediate operation and then providesthe destination information to switch SWB without further contact withthe terminal modem 12. No validation lookup is necessary as theimmediate mode indicates that the access is authorized. Switch SWB thenbegins the ring generation process. This entire time from LEC 17 pickupto the end of ring generation is approximately 0.7 seconds in theaverage case. Again it is noted that the ring detection by the channelunit 24 is preferably done by conventional A and B signalling elementsof either loop start or E & M signalling. Concurrently with this VPNfeature lookup, call setup and ring generation, the terminal modem 12will be providing the originate carrier, so that after the channel unit24 detects the call, timing is as in FIG. 7. This case is also secureand no login procedure is required. Portion A is thus approximately 1.4seconds, while Portion B is approximately 0.7 seconds, with Portions Cand D remaining as in FIG. 7.

It is noted that timing sequences for immediate, MF Switched Access VPNand delayed, interoperable Switched Access VPN have not been provided.The Portion B times are the only ones which change, based on thedifferent case. The two non-illustrated cases having timings between thetwo illustrated cases. The immediate, MF case includes the ANIinformation forwarding period, the switch SWA feature lookup and thecall setup and ring generation. The delayed, interoperable case includesthe ANI information forwarding, the return dial tone, the dialing, thesecond validation lookup, and the call setup and ring generation, aspreviously discussed.

While the above description has focused on communication of purchase ortransaction information between a remote POS terminal and a central hostcomputer center, it is understood that the techniques, embodiments andmethods of the present invention can be used between any two systemswhich must communicate any type of information over telephone lines.Examples of the systems, which can be combined in numerous ways, includeindependent data networks, packet switches, local area networks (LANs)having attached modems, individual personal computers and so on. Onesystem will be placing the call or originating the communication andthus be analogous to the remote terminal and the other system will bereceiving the call or answering the request and thus be analogous to thehost computer center.

The foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape, materials, components, circuit elements, wiring connections andcontacts, as well as in the details of the illustrated circuitry,construction, method of operation, timing, tones and protocols employedmay be made without departing from the spirit of the invention.

Various embodiments of the present invention, particularly those ofFIGS. 5, 7 and 8 require modifications of the modems conventionally usedfor communication between the host and the remote terminal. From thedescription set forth herein, these modifications will be obvious tothose skilled in the art without departing from the scope of theinvention set forth in the following claims.

I claim:
 1. A method of transmitting confidential data between aparticular remote modem of a plurality of remote modems and a hostcomputer having a host modem capable of being connected to any of theplurality of remote modems, comprising the steps of:the particularremote modem seizing a telephone line; determining the seizure of thetelephone lien by the particular remote modem and initiating a securetelephone connection sequence to the host modem, said sequence beingcompleted only if the remote modem has been previously authorized to beconnected to the host modem, said sequence being concluded by providinga ring signal to the host modem; the host modem seizing the telephoneline and providing an answer tone upon receipt of the ring signal; theparticular remote and host modems completing a baud rate determinationafter the answer tone is provided; providing indication from the hostmodem to the host computer that communication has been established andestablishing a link between the host modem and the host computer;transmitting a transaction commence signal to the particular remotemodem, said transaction commence signal being transmitted without alogin procedure being performed; and transmitting confidential databetween the particular remote modem and the host modem.
 2. A method ofclaim 1, wherein the particular remote and host modems are selected tooperate at fixed, common baud rates without baud rate determinationhandshaking.
 3. A method of connecting a remote modem to a host computerhaving a host modem, comprising the steps of:the remote modem seizing atelephone line; determining the seizure of the telephone line by theremote modem and initiating a telephone connection sequence to the hostmodem, said sequence being completed by providing a ring signal to thehost modem; the remote modem providing an originate carrier prior to thecompletion of providing the ring signal to initiate a modem handshake;the host modem sensing the ring signal and seizing the telephone line inresponse thereto and monitoring for the originate carrier; the hostmodem providing an answer carrier after determining the presence of theoriginate carrier to complete the modem handshake; providing indicationfrom the host modem to the host computer that communication has beenestablished and establishing a link between the host modem and the hostcomputer; and transmitting a transaction commence signal to the remotemodem after the link is established.
 4. The method of claim 3, whereinthe host modem provides the answer carrier without a silent intervalafter seizing the telephone line.
 5. The method of claim 3, wherein thetransaction commence signal is transmitted without a login procedurebeing performed.
 6. The method of claim 3, whereinif the host modemfails to determine the presence of the originate carrier within apredetermined time, the host modem provides an answer tone and theremote and host modems complete a carrier handshake, prior to providingthe communication established indication.
 7. The method of claim 3,wherein the ring signal is provided to the host modem only for a periodsufficient to allow detection by the host modem.